| 摘要 |
1,133,215. Alumina. HALCON INTERNATIONAL Inc. 17 Dec., 1965 [18 Dec., 1964], No. 53639/65. Heading C1A. [Also in Division C2] Activated aluminas, which are at least 99% by wt. pure and preferably have a surface area greater than 10 m<SP>2</SP>/g., are subjected to heat treatment and, optionally, doping to give improved catalyst supports. The heat treatment may be at 500-2000‹ C. for 1-100 hrs. Heating, and subsequent cooling, are preferably effected at a slow rate. Particular improvement in gamma-alumina is observed and is attributed to the formation of eta- and thetaalumina. The aluminas may be doped by the addition of 0À01-50 gram atoms of Sb, Ti, Sn or W, in the oxide form, per 100 moles. Impregnation with the dopand is accomplished by conventional methods, e.g. by treating the alumina with a solution of a decomposable salt of the metal. It is suggested that the alumina crystal is stabilized in the presence of the dopand. It is preferred to introduce the dopand before subjecting the alumina to the heat treatment. Examples 1, 3 and 4 describe the heat treatment of doping of various forms of alumina. |
